. >> reporter: he refused to release his tax returns, allowing newt gingrich to take south carolina. >> we proved here in south carolina we beat big money. >> reporter: but that big money eventually cleared the field and romney set his sights on the president. >> it's still about the economy. and we're not stupid. >> reporter: at number nine, bang. >> your punishment must be more severe. >> reporter: not that one, that one. almost as soon as mitt romney locked up the nomination, bane capital was savaged by democratic superpacs and the obama campaign. >> like a vampire. sucking the life out of us. >> reporter: the attack ads put romney on defense for months. >> there's nothing wrong with being associated with bane capital for months. >> reporter: the president also got a lift from the supreme court which at number eight upheld his embattled health care law, so romney vowed to strike it down himself. >> i'm that one that's going to get rid of obama care. >> reporter: number seven, gas. >> governor romney, do you feel your gaffes have overshadowed your trip? >> reporter: his missteps of